I would start by eating more calorie dense foods in smaller portions more often. So for breakfast, having some sourdough with a nut spread, avo and ricotta or melted cheese. Morning tea could be a slice of dense rich fruit cake. Lunch could be a pasta meal with legumes or eggs and a creamy sauce like alfredo or carbonara. Afternoon tea could be some trail mix. or a peanut butter sandwich. Dinner could be anything but serve with either potatoes, rice or pasta. Desert or supper could be a hot full fat milk with a banana on the side.
Nuts are very calorie dense and great for you. so are seeds.
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I love diggin' in the dirt
With just a pick and brush
Finding fossils is my aim
So I'm never in a rush